The Assignee of the present invention, M&M Precision Systems Corporation, has commercialized prior monitoring systems for determining or confirming the shape of a machined item such as a gear and the like. These prior art monitoring systems are commercially sold under the designation Model Numbers 3012, 3015, 3018, 3025, 3040 and 3060 where the last two digits indicate the diameter of the workpieces (in inches) the system is capable of monitoring.
The prior art systems sold by the Assignee of the invention include a moveable frame mounted to a base and include a drive system for moving a stylus or probe along three independent directions by controlled energization of multiple drive motors.
An arm that extends away from the frame has a stylus at one end which comes into contact with the object under examination. The stylus includes an LVDT monitoring probe that produces an output signal related to the position of a moveable probe member with respect to a probe body. Through a controlled monitoring of the output signals from the probe, and controlled movement of the frame, including a feedback monitoring of optical encoder signals as the frame moves, the monitoring system can accurately determine the position of the moveable probe tip. This allows the monitoring system to accurately compare any curve on a surface of a machined part with the desired shape of that surface. Alternately the monitoring system can test an unknown surface and store a representation of the part for later use as a standard.
In accordance with the prior art monitoring systems, the object under examination is supported on a turntable and held in place by a clamping member. Once the object has been secured to the turntable, controlled energization of a turntable drive causes the object to rotate. Precise control over the turntable rotation is achieved by controlled actuation of the turntable motor.
The prior art systems sold by the assignee of the present invention have particular utility in confirming the shape of an object having regularly occurring variations in contour. An example of such an object is a gear that has gear teeth spaced at regular intervals about the circumference of the gear. One use of the prior art monitoring systems is to detect differences between the desired shape of a gear and the actual shape of a gear that has been machined to assure that a desired degree of accuracy has been achieved. If the gear is not up to specifications corrective steps are taken to achieve more precision in the manufacture of the gear.